Footwear has undergone significant evolutionary advances in technology, particularly since the development of the electrodynogram which has permitted researchers to measure dynamic forces and to better understand biomechanical action of a human foot within a shoe while the wearer is walking or running. Using this tool, many researchers have made technological advances directed towards the mid-sole of a shoe. Since the mid-sole functions primarily as a suspension system of the sole of the foot, and often provides both protective cushioning and a stable platform for the wearer's foot, many conventional technologies have focused on cushioning the impact associated with foot strike by varying the spring coefficients in the mid-sole to dispense shock.
In my earlier U.S. Pat. No. 4,597,195 I describe a discovery of a then previously misunderstood phenomena, functional hallux limitus, that is believed to affect a majority of the population. To treat functional hallux limitus I created an improved shoe sole design which permits the first metatarsal to better achieve plantarflex relative to the great toe and remaining metatarsal heads. As explained in my aforesaid '195 patent, plantarflex allows for the extension of the human great toe during human gate cycle in an efficient fashion. More particularly in accordance with my prior '195 patent, I created a human shoe sole having an area of reduced support underlying substantially only the location of the first metatarsal head of the wearer's foot. As described in my '195 patent, providing an area of reduced support substantially only under the head of the first metatarsal encourages eversion and plantarflexion of the first metatarsal head as weight shifts from the heel to the first ray. Thus the normal functioning of the foot for plantarflexion and supination is encouraged with beneficial results for improved walking comfort and shock absorption on subsequent heel contact. Following my discovery millions of pairs of shoes have been manufactured with foot beds having an area of reduced support underlying substantially only the location of the first metatarsal head of the wearer's foot, to encourage plantarflexion of the first metatarsal head.